IPv4 Subnet Calculator
Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.
private IP (RFC 1918)10.51.208.0/20
network10.51.208.0/20
broadcast10.51.223.255
first host10.51.208.1
last host10.51.223.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classA
ipcalc 10.51.208.0/20
address00001010.00110011.11010000.00000000
subnet mask11111111.11111111.11110000.00000000
network00001010.00110011.11010000.00000000
broadcast00001010.00110011.11011111.11111111
green = network part, grey = host part
hex0x0a33d000
decimal171167744
reverse dns0.208.51.10.in-addr.arpa
ipv4-mapped::ffff:a33:d000
/20 split into /27 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.51.208.0/27 | 10.51.208.1 – 10.51.208.30 | 10.51.208.31 |
| 2 | 10.51.208.32/27 | 10.51.208.33 – 10.51.208.62 | 10.51.208.63 |
| 3 | 10.51.208.64/27 | 10.51.208.65 – 10.51.208.94 | 10.51.208.95 |
| 4 | 10.51.208.96/27 | 10.51.208.97 – 10.51.208.126 | 10.51.208.127 |
| 5 | 10.51.208.128/27 | 10.51.208.129 – 10.51.208.158 | 10.51.208.159 |
| 6 | 10.51.208.160/27 | 10.51.208.161 – 10.51.208.190 | 10.51.208.191 |
| 7 | 10.51.208.192/27 | 10.51.208.193 – 10.51.208.222 | 10.51.208.223 |
| 8 | 10.51.208.224/27 | 10.51.208.225 – 10.51.208.254 | 10.51.208.255 |
| 9 | 10.51.209.0/27 | 10.51.209.1 – 10.51.209.30 | 10.51.209.31 |
| 10 | 10.51.209.32/27 | 10.51.209.33 – 10.51.209.62 | 10.51.209.63 |
| 11 | 10.51.209.64/27 | 10.51.209.65 – 10.51.209.94 | 10.51.209.95 |
| 12 | 10.51.209.96/27 | 10.51.209.97 – 10.51.209.126 | 10.51.209.127 |
| 13 | 10.51.209.128/27 | 10.51.209.129 – 10.51.209.158 | 10.51.209.159 |
| 14 | 10.51.209.160/27 | 10.51.209.161 – 10.51.209.190 | 10.51.209.191 |
| 15 | 10.51.209.192/27 | 10.51.209.193 – 10.51.209.222 | 10.51.209.223 |
| 16 | 10.51.209.224/27 | 10.51.209.225 – 10.51.209.254 | 10.51.209.255 |
| 17 | 10.51.210.0/27 | 10.51.210.1 – 10.51.210.30 | 10.51.210.31 |
| 18 | 10.51.210.32/27 | 10.51.210.33 – 10.51.210.62 | 10.51.210.63 |
| 19 | 10.51.210.64/27 | 10.51.210.65 – 10.51.210.94 | 10.51.210.95 |
| 20 | 10.51.210.96/27 | 10.51.210.97 – 10.51.210.126 | 10.51.210.127 |
| 21 | 10.51.210.128/27 | 10.51.210.129 – 10.51.210.158 | 10.51.210.159 |
| 22 | 10.51.210.160/27 | 10.51.210.161 – 10.51.210.190 | 10.51.210.191 |
| 23 | 10.51.210.192/27 | 10.51.210.193 – 10.51.210.222 | 10.51.210.223 |
| 24 | 10.51.210.224/27 | 10.51.210.225 – 10.51.210.254 | 10.51.210.255 |
| 25 | 10.51.211.0/27 | 10.51.211.1 – 10.51.211.30 | 10.51.211.31 |
| 26 | 10.51.211.32/27 | 10.51.211.33 – 10.51.211.62 | 10.51.211.63 |
| 27 | 10.51.211.64/27 | 10.51.211.65 – 10.51.211.94 | 10.51.211.95 |
| 28 | 10.51.211.96/27 | 10.51.211.97 – 10.51.211.126 | 10.51.211.127 |
| 29 | 10.51.211.128/27 | 10.51.211.129 – 10.51.211.158 | 10.51.211.159 |
| 30 | 10.51.211.160/27 | 10.51.211.161 – 10.51.211.190 | 10.51.211.191 |
| 31 | 10.51.211.192/27 | 10.51.211.193 – 10.51.211.222 | 10.51.211.223 |
| 32 | 10.51.211.224/27 | 10.51.211.225 – 10.51.211.254 | 10.51.211.255 |
| 33 | 10.51.212.0/27 | 10.51.212.1 – 10.51.212.30 | 10.51.212.31 |
| 34 | 10.51.212.32/27 | 10.51.212.33 – 10.51.212.62 | 10.51.212.63 |
| 35 | 10.51.212.64/27 | 10.51.212.65 – 10.51.212.94 | 10.51.212.95 |
| 36 | 10.51.212.96/27 | 10.51.212.97 – 10.51.212.126 | 10.51.212.127 |
| 37 | 10.51.212.128/27 | 10.51.212.129 – 10.51.212.158 | 10.51.212.159 |
| 38 | 10.51.212.160/27 | 10.51.212.161 – 10.51.212.190 | 10.51.212.191 |
| 39 | 10.51.212.192/27 | 10.51.212.193 – 10.51.212.222 | 10.51.212.223 |
| 40 | 10.51.212.224/27 | 10.51.212.225 – 10.51.212.254 | 10.51.212.255 |
| 41 | 10.51.213.0/27 | 10.51.213.1 – 10.51.213.30 | 10.51.213.31 |
| 42 | 10.51.213.32/27 | 10.51.213.33 – 10.51.213.62 | 10.51.213.63 |
| 43 | 10.51.213.64/27 | 10.51.213.65 – 10.51.213.94 | 10.51.213.95 |
| 44 | 10.51.213.96/27 | 10.51.213.97 – 10.51.213.126 | 10.51.213.127 |
| 45 | 10.51.213.128/27 | 10.51.213.129 – 10.51.213.158 | 10.51.213.159 |
| 46 | 10.51.213.160/27 | 10.51.213.161 – 10.51.213.190 | 10.51.213.191 |
| 47 | 10.51.213.192/27 | 10.51.213.193 – 10.51.213.222 | 10.51.213.223 |
| 48 | 10.51.213.224/27 | 10.51.213.225 – 10.51.213.254 | 10.51.213.255 |
| 49 | 10.51.214.0/27 | 10.51.214.1 – 10.51.214.30 | 10.51.214.31 |
| 50 | 10.51.214.32/27 | 10.51.214.33 – 10.51.214.62 | 10.51.214.63 |
| 51 | 10.51.214.64/27 | 10.51.214.65 – 10.51.214.94 | 10.51.214.95 |
| 52 | 10.51.214.96/27 | 10.51.214.97 – 10.51.214.126 | 10.51.214.127 |
| 53 | 10.51.214.128/27 | 10.51.214.129 – 10.51.214.158 | 10.51.214.159 |
| 54 | 10.51.214.160/27 | 10.51.214.161 – 10.51.214.190 | 10.51.214.191 |
| 55 | 10.51.214.192/27 | 10.51.214.193 – 10.51.214.222 | 10.51.214.223 |
| 56 | 10.51.214.224/27 | 10.51.214.225 – 10.51.214.254 | 10.51.214.255 |
| 57 | 10.51.215.0/27 | 10.51.215.1 – 10.51.215.30 | 10.51.215.31 |
| 58 | 10.51.215.32/27 | 10.51.215.33 – 10.51.215.62 | 10.51.215.63 |
| 59 | 10.51.215.64/27 | 10.51.215.65 – 10.51.215.94 | 10.51.215.95 |
| 60 | 10.51.215.96/27 | 10.51.215.97 – 10.51.215.126 | 10.51.215.127 |
| 61 | 10.51.215.128/27 | 10.51.215.129 – 10.51.215.158 | 10.51.215.159 |
| 62 | 10.51.215.160/27 | 10.51.215.161 – 10.51.215.190 | 10.51.215.191 |
| 63 | 10.51.215.192/27 | 10.51.215.193 – 10.51.215.222 | 10.51.215.223 |
| 64 | 10.51.215.224/27 | 10.51.215.225 – 10.51.215.254 | 10.51.215.255 |
| 65 | 10.51.216.0/27 | 10.51.216.1 – 10.51.216.30 | 10.51.216.31 |
| 66 | 10.51.216.32/27 | 10.51.216.33 – 10.51.216.62 | 10.51.216.63 |
| 67 | 10.51.216.64/27 | 10.51.216.65 – 10.51.216.94 | 10.51.216.95 |
| 68 | 10.51.216.96/27 | 10.51.216.97 – 10.51.216.126 | 10.51.216.127 |
| 69 | 10.51.216.128/27 | 10.51.216.129 – 10.51.216.158 | 10.51.216.159 |
| 70 | 10.51.216.160/27 | 10.51.216.161 – 10.51.216.190 | 10.51.216.191 |
| 71 | 10.51.216.192/27 | 10.51.216.193 – 10.51.216.222 | 10.51.216.223 |
| 72 | 10.51.216.224/27 | 10.51.216.225 – 10.51.216.254 | 10.51.216.255 |
| 73 | 10.51.217.0/27 | 10.51.217.1 – 10.51.217.30 | 10.51.217.31 |
| 74 | 10.51.217.32/27 | 10.51.217.33 – 10.51.217.62 | 10.51.217.63 |
| 75 | 10.51.217.64/27 | 10.51.217.65 – 10.51.217.94 | 10.51.217.95 |
| 76 | 10.51.217.96/27 | 10.51.217.97 – 10.51.217.126 | 10.51.217.127 |
| 77 | 10.51.217.128/27 | 10.51.217.129 – 10.51.217.158 | 10.51.217.159 |
| 78 | 10.51.217.160/27 | 10.51.217.161 – 10.51.217.190 | 10.51.217.191 |
| 79 | 10.51.217.192/27 | 10.51.217.193 – 10.51.217.222 | 10.51.217.223 |
| 80 | 10.51.217.224/27 | 10.51.217.225 – 10.51.217.254 | 10.51.217.255 |
| 81 | 10.51.218.0/27 | 10.51.218.1 – 10.51.218.30 | 10.51.218.31 |
| 82 | 10.51.218.32/27 | 10.51.218.33 – 10.51.218.62 | 10.51.218.63 |
| 83 | 10.51.218.64/27 | 10.51.218.65 – 10.51.218.94 | 10.51.218.95 |
| 84 | 10.51.218.96/27 | 10.51.218.97 – 10.51.218.126 | 10.51.218.127 |
| 85 | 10.51.218.128/27 | 10.51.218.129 – 10.51.218.158 | 10.51.218.159 |
| 86 | 10.51.218.160/27 | 10.51.218.161 – 10.51.218.190 | 10.51.218.191 |
| 87 | 10.51.218.192/27 | 10.51.218.193 – 10.51.218.222 | 10.51.218.223 |
| 88 | 10.51.218.224/27 | 10.51.218.225 – 10.51.218.254 | 10.51.218.255 |
| 89 | 10.51.219.0/27 | 10.51.219.1 – 10.51.219.30 | 10.51.219.31 |
| 90 | 10.51.219.32/27 | 10.51.219.33 – 10.51.219.62 | 10.51.219.63 |
| 91 | 10.51.219.64/27 | 10.51.219.65 – 10.51.219.94 | 10.51.219.95 |
| 92 | 10.51.219.96/27 | 10.51.219.97 – 10.51.219.126 | 10.51.219.127 |
| 93 | 10.51.219.128/27 | 10.51.219.129 – 10.51.219.158 | 10.51.219.159 |
| 94 | 10.51.219.160/27 | 10.51.219.161 – 10.51.219.190 | 10.51.219.191 |
| 95 | 10.51.219.192/27 | 10.51.219.193 – 10.51.219.222 | 10.51.219.223 |
| 96 | 10.51.219.224/27 | 10.51.219.225 – 10.51.219.254 | 10.51.219.255 |
| 97 | 10.51.220.0/27 | 10.51.220.1 – 10.51.220.30 | 10.51.220.31 |
| 98 | 10.51.220.32/27 | 10.51.220.33 – 10.51.220.62 | 10.51.220.63 |
| 99 | 10.51.220.64/27 | 10.51.220.65 – 10.51.220.94 | 10.51.220.95 |
| 100 | 10.51.220.96/27 | 10.51.220.97 – 10.51.220.126 | 10.51.220.127 |
| 101 | 10.51.220.128/27 | 10.51.220.129 – 10.51.220.158 | 10.51.220.159 |
| 102 | 10.51.220.160/27 | 10.51.220.161 – 10.51.220.190 | 10.51.220.191 |
| 103 | 10.51.220.192/27 | 10.51.220.193 – 10.51.220.222 | 10.51.220.223 |
| 104 | 10.51.220.224/27 | 10.51.220.225 – 10.51.220.254 | 10.51.220.255 |
| 105 | 10.51.221.0/27 | 10.51.221.1 – 10.51.221.30 | 10.51.221.31 |
| 106 | 10.51.221.32/27 | 10.51.221.33 – 10.51.221.62 | 10.51.221.63 |
| 107 | 10.51.221.64/27 | 10.51.221.65 – 10.51.221.94 | 10.51.221.95 |
| 108 | 10.51.221.96/27 | 10.51.221.97 – 10.51.221.126 | 10.51.221.127 |
| 109 | 10.51.221.128/27 | 10.51.221.129 – 10.51.221.158 | 10.51.221.159 |
| 110 | 10.51.221.160/27 | 10.51.221.161 – 10.51.221.190 | 10.51.221.191 |
| 111 | 10.51.221.192/27 | 10.51.221.193 – 10.51.221.222 | 10.51.221.223 |
| 112 | 10.51.221.224/27 | 10.51.221.225 – 10.51.221.254 | 10.51.221.255 |
| 113 | 10.51.222.0/27 | 10.51.222.1 – 10.51.222.30 | 10.51.222.31 |
| 114 | 10.51.222.32/27 | 10.51.222.33 – 10.51.222.62 | 10.51.222.63 |
| 115 | 10.51.222.64/27 | 10.51.222.65 – 10.51.222.94 | 10.51.222.95 |
| 116 | 10.51.222.96/27 | 10.51.222.97 – 10.51.222.126 | 10.51.222.127 |
| 117 | 10.51.222.128/27 | 10.51.222.129 – 10.51.222.158 | 10.51.222.159 |
| 118 | 10.51.222.160/27 | 10.51.222.161 – 10.51.222.190 | 10.51.222.191 |
| 119 | 10.51.222.192/27 | 10.51.222.193 – 10.51.222.222 | 10.51.222.223 |
| 120 | 10.51.222.224/27 | 10.51.222.225 – 10.51.222.254 | 10.51.222.255 |
| 121 | 10.51.223.0/27 | 10.51.223.1 – 10.51.223.30 | 10.51.223.31 |
| 122 | 10.51.223.32/27 | 10.51.223.33 – 10.51.223.62 | 10.51.223.63 |
| 123 | 10.51.223.64/27 | 10.51.223.65 – 10.51.223.94 | 10.51.223.95 |
| 124 | 10.51.223.96/27 | 10.51.223.97 – 10.51.223.126 | 10.51.223.127 |
| 125 | 10.51.223.128/27 | 10.51.223.129 – 10.51.223.158 | 10.51.223.159 |
| 126 | 10.51.223.160/27 | 10.51.223.161 – 10.51.223.190 | 10.51.223.191 |
| 127 | 10.51.223.192/27 | 10.51.223.193 – 10.51.223.222 | 10.51.223.223 |
| 128 | 10.51.223.224/27 | 10.51.223.225 – 10.51.223.254 | 10.51.223.255 |
01 / table
IPv4 CIDR prefix table.
Click a prefix longer than your network to split it into subnets.
| prefix | subnet mask | addresses | hosts | in your /20 |
|---|---|---|---|---|
| /0 | 0.0.0.0 | 4,294,967,296 | 4,294,967,294 | - |
| /1 | 128.0.0.0 | 2,147,483,648 | 2,147,483,646 | - |
| /2 | 192.0.0.0 | 1,073,741,824 | 1,073,741,822 | - |
| /3 | 224.0.0.0 | 536,870,912 | 536,870,910 | - |
| /4 | 240.0.0.0 | 268,435,456 | 268,435,454 | - |
| /5 | 248.0.0.0 | 134,217,728 | 134,217,726 | - |
| /6 | 252.0.0.0 | 67,108,864 | 67,108,862 | - |
| /7 | 254.0.0.0 | 33,554,432 | 33,554,430 | - |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | - |
| /9 | 255.128.0.0 | 8,388,608 | 8,388,606 | - |
| /10 | 255.192.0.0 | 4,194,304 | 4,194,302 | - |
| /11 | 255.224.0.0 | 2,097,152 | 2,097,150 | - |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | - |
| /13 | 255.248.0.0 | 524,288 | 524,286 | - |
| /14 | 255.252.0.0 | 262,144 | 262,142 | - |
| /15 | 255.254.0.0 | 131,072 | 131,070 | - |
| /16 | 255.255.0.0 | 65,536 | 65,534 | - |
| /17 | 255.255.128.0 | 32,768 | 32,766 | - |
| /18 | 255.255.192.0 | 16,384 | 16,382 | - |
| /19 | 255.255.224.0 | 8,192 | 8,190 | - |
| /20 | 255.255.240.0 | 4,096 | 4,094 | 1 |
| /21 | 255.255.248.0 | 2,048 | 2,046 | 2 split → |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 4 split → |
| /23 | 255.255.254.0 | 512 | 510 | 8 split → |
| /24 | 255.255.255.0 | 256 | 254 | 16 split → |
| /25 | 255.255.255.128 | 128 | 126 | 32 split → |
| /26 | 255.255.255.192 | 64 | 62 | 64 split → |
| /27 | 255.255.255.224 | 32 | 30 | 128 split → |
| /28 | 255.255.255.240 | 16 | 14 | 256 split → |
| /29 | 255.255.255.248 | 8 | 6 | 512 split → |
| /30 | 255.255.255.252 | 4 | 2 | 1,024 split → |
| /31 | 255.255.255.254 | 2 | 2 | 2,048 split → |
| /32 | 255.255.255.255 | 1 | 1 | 4,096 split → |
02 / faq
About this calculator.
How do I use this subnet calculator?
▼
Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.
Why are usable hosts always 2 fewer?
▼
The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.
Can I use it from a terminal?
▼
Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.